PSC and right-sided colorectal cancer

[Guest guest]

Inflamm Bowel Dis. 2009 Feb 19. [Epub ahead of print]

More right-sided IBD-associated colorectal cancer in patients with

primary sclerosing cholangitis.

Claessen MM, Lutgens MW, van Buuren HR, Oldenburg B, Stokkers PC, van

der Woude CJ, Hommes DW, de Jong DJ, Dijkstra G, van Bodegraven AA,

Siersema PD, Vleggaar FP

Department of Gastroenterology and Hepatology, University Medical

Center Utrecht, The Netherlands.

Background: Patients with inflammatory bowel disease (IBD) and

concurrent primary sclerosing cholangitis (PSC) have a higher risk of

developing colorectal cancer (CRC) than IBD patients without PSC. The

aim of this study was to investigate potential clinical differences

between patients with CRC in IBD and those with CRC in IBD and PSC,

as this may lead to improved knowledge of underlying

pathophysiological mechanisms of CRC development. Methods: The

retrospective study from 1980-2006 involved 7 Dutch university

medical centers. Clinical data were retrieved from cases identified

using the national pathology database (PALGA). Results: In total, 27

IBD-CRC patients with PSC (70% male) and 127 IBD-CRC patients without

PSC (59% male) were included. CRC-related mortality was not different

between groups (30% versus 19%, P = 0.32); however, survival for

cases with PSC after diagnosing CRC was lower (5-year survival: 40%

versus 75% P = 0.001). Right-sided tumors were more prevalent in the

PSC group (67% versus 36%, P = 0.006); adjusted for age, sex, and

extent of IBD, this difference remained significant (odds ratio: 4.8,

95% confidence interval [CI] 2.0-11.8). In addition, tumors in

individuals with PSC were significantly more advanced. Conclusions:

The right colon is the predilection site for development of colonic

malignancies in patients with PSC and IBD. When such patients are

diagnosed with cancer they tend to have more advanced tumors than

patients with IBD without concurrent PSC, and the overall prognosis

is worse. Furthermore, the higher frequency of right-sided tumors in

patients with PSC suggests a different pathogenesis between patients

with PSC and IBD and those with IBD alone. PMID: 19229982.

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Right-sided colorectal cancer seems to be associated with high

concentrations of secondary bile acids, such as deoxycholic acid, in

the colon, and this is where ursodeoxycholic acid could come into

play as a colon cancer preventive agent:

http://www.medscape.com/viewprogram/8334_pnt

" In theory, carcinogenic secondary bile acids, such as deoxycholic

acid (which is abnormally high in patients with cholestasis), are

presented to the right side of the colon in higher concentrations

than the left side. Reducing the concentration of these secondary

bile acids with UDCA could have chemopreventive effects. "

Dave

(father of (23); PSC 07/03; UC 08/03)